Fluidic valve modulator

ABSTRACT

A fluidic valve control which may be operated in a time modulated mode is disclosed. The position of a valve member is modulated by means of the generation of Bernoulli forces in a fluidic actuator which is mechanically coupled to the valve.

United States Patent [191 [111 3,829,058 Andersen Aug. 13, 1974 FLUIDIC VALVE MODULATOR 2,417,994 3/1947 Sheets 251/24 3,135,281 61964 M 251 33 X [75] Inventor: JSePh J'Andmell Bnstol Com 3,521,535 711970 03:53? 91/47 [73] Assignee: Chandler Evans Inc., West Hartford, Conn. I Filed: y 1972 Primary ExammerArnold Rosenthal [21] Appl. No.: 272,755

52 us. c1 251/25, 251/63.6, 1.37/625.66, [57] ABSTRACT 251/24 [51] Int. Cl. Fl6k 31/43 A fluidi al ntr l which ay e operated in a [58] Field of Search 251/24, 63.6, 33, 25; im m la e mo e is disclosed. The position of a 137/625 66, 596,18 valve member is modulated by means of the generation of Bernoulli forces in a fluidic actuator which is [56] References Cited mechanically coupled to the valve.

UNITED STATES PATENTS 2,185,671 9 Claims, 1 Drawing Figure 1/1940 Kimball 251/33 X FLUIDIC ACTUATOR PATENTED 31974 3. 829.058

[7 5o FLUIDIC ACTUATOR,

FLUIDIC VALVE MODULATOR BACKGROUND OF THE INVENTION:

vention is particularly well suited for use in time modulated pneumatically actuated position control mechanisms of the type disclosed in US. Pat. No. 3,521,535 issued July 21, 1970 to John A. Olerich and assigned to the assignee of the present invention. Prior art time modulated control mechanisms, as exemplified bythe referenced patent, have utilized a solenoid operated control valve of the type which may best be seen from FIG. 4 of U.S. Pat. No. 3,521,535. Due to the fact that the prior art time modulated pneumatically actuated control mechanisms employed a solenoid operated valve, electronic circuitry was necessary to generate the valve control signals and a comparatively heavy power source, typically a battery, was necessary to supply current for energizing the valve control solenoid.

While the prior art control mechanisms of the type briefly described above have performed admirably, there has been a long standing desire to provide replacement therefore in the form of an entirely fluidic system. The ability to perform the functions of the prior art electrical solenoid valve by means of a fluidic device would offer the advantages of reduction in weight and initial system cost as well as enhancing system reliability. The characteristics of weight and reliability are, of course, of extreme interest in such environments as missile control systems.

SUMMARY OF THE lNVENTlON The present invention constitutes a novel departure from the prior'art, as briefly described above, by providing a fluidic solenoid valve which performs the same functions in a time modulated pneumatically actuated position control mechanism as did the electronic solenoid valves previously employed. In accordance with the present invention a valveplunger positions the ball poppet of a three-way ball flow control valve in a pulse width or time modulated'fashion to develop the desired quasi-proportional flow or output pressure. The means by which modulation of the ball poppet is achieved comprises a ball enclosed in a spherical chamber and attached to the valve plunger. Introduction of a fluid at low pressure to the ball chamber at a point disposed oppositely to the point of attachment of the ball to the valve plunger results in the generation of fluidic momentum forces. These momentum or Bernoulli forces overcome a pre-load spring force exerted on the plunger and lift the plunger away from the ball poppet. Pressure forces thereupon move the ball poppet from afirst seat to a second seat and allow power flow from a supply to the load. The control fluid is introduced to the ball chamber in the form of pulses and when each low pressure control pulse is removed the plunger spring drives the plunger downwardly thus returning the ball poppet to its initial position. Return of the ball poppet to the first seat typically disconnects the supply from the load and permits flow from the load to a sump or overboard dump port via an aperture in the second seat.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing which is a cross-sectional, side elevation view of a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawing, the invention generally comprises a three-way ball valve mechanism, indicated generally at 10, and a fluidic control system for Considering first the ball valve subsystem 10, it is to be noted that this portion of the fluidic solenoid valve I of the present invention is designed in accordance with the prior art. A pressurized source of fluid, not-shown, is connected to the ball valve supply port 14. The pressurized fluid delivered to the device via port 14 will, in the manner to be described below, be modulated and positive fluid or pressure pulses will be delivered to a pneumatic or hydraulic load via a first discharge port 16. During periods when supply pressure is not delivered to the load, fluid previously delivered to the load will flow in the reverse direction through port 16 to a passage 18 which terminates in a further discharge port 20; port 20 either dumping overboard to the ambient atmosphere or returning the fluid to a sump.

The actual flow control mechanism of. the three-way ball valve comprises a ball poppet 22, a ball plunger 24, and a valve spring 26. Spring 26 is coaxial with plunger 24 and is in compression against a shoulder 47 provided on an extension of housing portion 46 of control mechanism 12 whereby the plunger is urged in the downward direction in the embodiment shown. The ball poppet 22 cooperates with oppositely disposed valve seat defining members to establish communication between the discharge port 16 and either the supply port 14 or passage 18; communication between the supply port '14 and discharge port- 16 being established with the ball in the raised position. With the ball held against the-lower seat due to the action of spring 26 as shown, fluid may pass around ball 22 in flowing from the load to port 20 via port 16, the open upper valve and passage 18. a

The fluidic control subsystem 12 for flow control valve 10 comprises a comparatively light weight ball 40 enclosed in a spherical chamber 42 defined by the upper and lower elements 44 and 46 respectively of a housing. Ball 40 is mechanically connected to the upper end of valve plunger 24 and the ball 40 is accordingly pulled downwardly by valve spring 26. Spherical chamber 42 is in communication, via a passage 48, with a fluidic oscillator 50. Oscillator 50 may be of the type well known in the art which switches an applied source between a pair of outlet ports. A source of fluid at a comparatively low pressure, not shown, is applied to oscillator 50 via connector 52. Oscillator 50 operates to establish communication between passage 48 and this low pressure source at the selected frequency of operation; i.e., as a result of the operation of oscillator 50 low pressure pulses are applied to spherical chamber 46. Spherical chamber 46 has a discharge port 54 which will typically be open to the ambient atmosphere.

In operation, the application of a low pressure-pulse to chamber 46 via passage 48 will result in fluid from the low pressure source, which will be at a pressure higher than ambient, flowing around ball 40 to port 54. This flow pulse provided by oscillator 50 will create a pressure differential about ball 40 and Bernoulli (fluid momentum) forces will be developed which will overcome the force exerted by spring 26 on plunger 24. Accordingly, ball 40 will move upwardly thereby lifting plunger 24 away from ball poppet 22. Pressure forces will thereupon move the ball from the lower seat to the upper seat and allow power flow from supply port 14 to the load via discharge port 16. When the low pressure control pulse is removed, the plunger spring will return the plunger and thus the ball poppet to the lower seat and flow through the device will be reversed and will pass from the load via port 16 to the sump or drain via passage 18 and port 20. Commensurate with prior art pulse width or time modulated control techniques, the pressure or flow to the load may thus be made quasi-proportional.

While a preferred embodiment has been shown and described various substitutions and modifications may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.

What is claimed is:

1. Apparatus for controlling the state of a fluid flow control device, the device including a movable valve member, said apparatus comprising:

housing means defining a chamber, said housing means being provided with at least a pair of passages for establishing fluid communication between said chamber and the exterior of the hous- I meais exterior of said housing and coupled to a first of said passages for delivering control pulses of fluid to said chamber, said control pulses being at a pressure in excess of that applied to the second of saidpassages whereby fluid delivered to said chamber for control purposes will flow out of said second passage;

flow responsive actuator means disposed for movement in said chamber, said actuator means being contoured such that flow across the surface thereof between said first and second passages creates a pressure differential across said actuator means whereby said actuator means is movable within said chamber in response to the application of a fluidic control pulse thereto;

means extending through said housing means for mechanically coupling said actuator means to the movable valve member; and

means biasing said actuator means in a first direction commensurate with a first state of the flow control device corresponding to a first position of the valve member, flow induced movements of said actuator means overcoming said biasing means and causing the valve member to assume a position commensurate with a second state of the flow control device.

2. The apparatus of claim 1 wherein said housing means defines a spherical chamber, ends of said first and second passages communicating with said chamber at points displaced about said chamber by an arc in excess of 3. The apparatus of claim 2 wherein said first passage and said coupling means are oppositely disposed with respect to said chamber.

4. The apparatus of claim 2 wherein said actuator means comprises:

a light weight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages generating momentum forces which move the ball toward said first passage.

5. The apparatus of claim 3 wherein said actuator means comprises:

a lightweight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages generating momentum forces which move the ball toward said first passage.-

6. The apparatus of claim 1 wherein said control pulse delivering means comprises:

a fluidic oscillator, the oscillator output pulses resulting in the flow control device being operated in a time modulated mode.

7. The apparatus of claim 6 wherein said housing means defines a spherical chamber, ends of said first and second passages communicating with said chamber at points displaced about said chamber by an arc in excess of 90.

8. The apparatus of claim 7 wherein said actuator means comprises:

a light weight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages corresponding to said oscillator output pulses generating momentum forces which move the ball toward said first passage.

9. The apparatus of claim 8 wherein said first passage and said coupling means are oppositely disposed with respect to said chamber and ball. 

1. Apparatus for controlling the state of a fluid flow control device, the device including a movable valve member, said apparatus comprising: housing means defining a chamber, said housing means being provided with at least a pair of passages for establishing fluid communication between said chamber and the exterior of the housing; means exterior of said housing and coupled to a first of said passages for delivering control pulses of fluid to said chamber, said control pulses being at a pressure in excess of that applied to the second of said passages whereby fluid delivered to said chamber for control purposes will flow out of said second passage; flow responsive actuator means disposed for movement in said chamber, said actuator means being contoured such that flow across the surface thereof between said first and second passages creates a pressure differential across said actuator means whereby said actuator means is movable within said chamber in response to the application of a fluidic control pulse thereto; means extending through said housing means for mechanically coupling said actuator means to the movable valve member; and means biasing said actuator means in a first direction commensurate with a first state of the flow control device corresponding to a first position of the valve member, flow induced movements of said actuator means overcoming said biasing means and causing the valve member to assume a position commensurate with a second state of the flow control device.
 2. The apparatus of claim 1 wherein said housing means defines a spherical chamber, ends of said first and second passages communicating with said chamber at points displaced about said chamber by an arc in excess of 90*.
 3. The apparatus of claim 2 wherein said first passage and said coupling means are oppositely disposed with respect to said chamber.
 4. The apparatus of claim 2 wherein said actuator means comprises: a light weight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages generating momentum forces which move the ball toward said first passage.
 5. The apparatus of claim 3 wherein said actuator means comprises: a light weight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages generating momentum forces which move the ball toward said first passage.
 6. The apparatus of claim 1 wherein said control pulse delivering means comprises: a fluidic oscillator, the oscillator output pulses resulting in the flow control device being operated in a time modulated mode.
 7. The apparatus of claim 6 wherein said housing means defines a spherical chamber, ends of said first and second passages communicating with said chamber at points displaced about said chamber by an arc in excess of 90*.
 8. The apparatus of claim 7 wherein said actuator means comprises: a light weight ball disposed in said chamber, the flow of fluid about said ball between said first and second passages corresponding to said oscillator output pulses generating momentum forces which move the ball toward said first passage.
 9. The apparatus of claim 8 wherein said first passage and said coupling means are oppositely disposed with respect to said chamber and ball. 